Conventional timing chain driving systems typically use a roller chain, a rollerless bushing chain, or a silent chain. It is also known to use a hybrid timing chain, in which links of a silent chain and links of a roller chain are combined, in conjunction with specially designed sprockets having plural sets of teeth for meshing with the rollers and with the silent chain teeth, respectively.
As shown in FIG. 21, this known hybrid timing chain driving system comprises a chain 510 in which link plates 511 on the outsides of the chain each have a pair of teeth so that they function as a silent chain, and toothless inner link plates 512 along with rollers 520 function as a roller chain. The link plates and rollers are connected by pins 530. As shown in FIG. 22, a sprocket 550 of the driving system has side teeth 552 for engagement with the silent chain teeth on plates 511. These teeth 552 are formed on the both sides of a central set of sprocket teeth 551 for engagement with the rollers 520.
An example of a typical hybrid chain transmission is described in Japanese Patent Publication No. Shoo 59-30936. In operation of the hybrid chain transmission, power is transmitted by engagement of the teeth of the link plates 511 with the side sprocket teeth 552, so that the transmission functions as a silent chain transmission. The rollers 520 abut the sprocket teeth 551 when the teeth of the link plates 511 become seated on the side sprocket teeth 552.